The state of possessing either a malfunctioning set of testicular apparatus or no testicular apparatus. This state of being is most common in canines, cats and whipped married men. The origin from the word stems from the distinction between one with a pair of testicular apparatus and one without said apparatus. The one with the apparatus can let nature continue whereas the one without the apparatus can't let nature continue, hence DE-NATURED.

My dog is now denatured as his testicles were duly ripped from his ballsack yesterday at the vet.

A: That man is being pushed around by his wife. He must be denatured.
B: Explains why they don't have kids.